Thread-controlling mechanism for sewing-machines.



1). W. GOREY. THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLIOATION FILED JUNE 3, 1904.

1,075,695. Patented 00t.14;,1913

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DANIEL W. COREY, OF ST. LOUIS, MISSOURI, ASSIGNOE TO UNION SPECIAL SEXVING MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

THREJQrD-GONTROLLING MECHANISM FOR SEWING-MACHINES.

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Application filed June 3,19%. Serial No. 211,030.

To all whom it may concern Be it known that I, DANIEL W. COREY, a citizen of the United States, residing at St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Thread-Controlling Mechanism for Sewing-Machines, of which the following is a description, reference being had to the accompanying drawing and to the letters and figures of reference marked thereon.

My invention relates to an improvement in sewing machines, and particularly to an improvement upon the Union Special zigzag and straight away-stitch machine, which is illustrated in the patent of R. G. Woodward'No. 890,582, granted June 9, 1908. .The'machine above referred to is used principally in connection with the closing of the uppers of shoes at the rear portion, the object being to first sew the two superposed edges of the upper together a short distance by a line of straight-away sewing, and then by a line of zig-zag sewing so that, when the pieces of leather are spread out flat, there will be no ridge upon the inside of the shoe, except at the very top of the rear part.

In practice, it has been found that when stitching the lighter grades of leather, such .as in the manufacture of fine shoes, with the ordinary tension devices adjusted for straightaway st-itclnng, when the z1gzag stitch was being sewed, the seam would be too tight, so that on such light goods, the stock is liable to be pulled together forming a ridge, there not being enough thread given up to allow the overstitched seam to lie fiat.

The object of the present invention is, therefore, to provide means for loosening up the tension on the thread when the machine operates to make thezig-zag stitches.

In carrying out the invention mechanisn: is provided whereby the tension on the thread may be varied when passing from the straightaway stitching to the zigzag stitching. As afurther means of ing in accomplishing this result, I prov de the presser foot with a tongue across which the needlelays its thread when forming the zigzag stitches-x The invr ntion consists in the matters hereinafter des :ribed and referred to in the appended clams.

gpec ificationof Letters Patent.

' vcntion.

Patented Got. '14, 1913.

The invention is illustrated in ings, in'which,

Figure 1 represents a front elevation of so much of the sewing machine, as, is necessary to a complete understanding of the invention, Fig. 2 is a perspective of the presser foot and a portion of the throat plate cooperating therewith, Fig. 3 is a top plan view of the*presser foot, and Fig. 4: represents the style of stitching accomplished on this machine.

In these drawings, A represents the bed plate of the machine, B the goose neck, C the needle lever, .N the needle bar, a the needle, and D the needle gate in which the needle bar reciprocates. The needle gate is connected to the depending arm 1, of the rock shaft 2, which is oscillated by the segthe drawthe gear wheel 4. The oscillation of the needle gate causes the needle to deposit the zigzag stitches. By means of the rod 5, which is under the control of the operator, the connection between the segment 3 and the rock shaft 2 is controlled so that the needle gate is either vibrated or remains at rest, thus depositing either the zig-zag or straight-away stitching. All of these parts are disclosed in detail in the patents granted to R. G. \Voodward, February 23, 190i, No. 753,187, and June 9th, 1908, No. 890,582, and will not need further description at this time as they form no part of my in- In the usual operation of this machine it has been found that the tension when adjusted properly for straightaway stitching; is too tight for zig-zag stitching, thus causing in light goods a rib where the goods should lie flat. I have, therefore, provided two tensions, Q, which is the ordinary tension, and P an auxiliary tension. An arm L is connected with the lever pivoted in the bracket '0' and operated by the rod 5 to control the position of the needle. This arm L has adjustably connected at its upper end a fork K provided with wedge shaped ends N which enter between the disks of the auxiliary tension P when the arm is raised, thus releasing the auxiliary tension from the'thread. This releasing of the auxiliary tension takes place when the' connection between the rock shaft 2 and the segment 3 is controlled, so as to cause the needle to vibrate to deposit the zigzag stitches. It will be noted that when the'operator m oves'the controller so as to change the character of the seam from .zig-zag stitching to straight-away stitching the auxiliary tension will be automatically released or applied to the needle thread. When sewing on heavy material and it is desired to maintain a constant tension onv the needletliread whether making straightaway or zigzag stitching the screw which connects the fork K to the arm L is loosened and the fork adjusted downward until it'is in a sition where it will not engage the tension disks in either position of thearin L.

As av further means for controlling the thread when makingthe zig-zag stitches, I have provided the presser foot S with a tongue T which lies in the path of vibration ofthe needle so that the said needle lays its thread over said tongue. As the goods are 'fed 'forWard-the'stitches slip 01f from the '.tongue. Thistongue serves to form slack.

. in the thread and retain the same so that' stitche will not be skipped as might occur with a loose tension. A similar tongue T, see Fig.0, is provided on the throat plate over'which the looper thread is drawn.

By the above described devices, I can produce a straightawaylstitclied seam .having forming mechanism, including a needle,

means for vibrating said needle laterally to form cross stitching, means for suspending the lateral vibrations of said needle, whereby a line of stitching may be produced which is substantially in line with one of the rows of needle punctures in the cross stitching, and a slack thread-forming finger located entirely at one side of the path of the needle,

when forming the straight-line of stitching and between the extreme lateral positions of the'needle when making the cross stitching,

wherebythe cross threads are laid over said thread finger.

2. In as'ewing-niacl-iine, the combination ofa Work support, apresser foot, :1 slack thread forming finger, stitch forming mechanism including a needle, means for vibrating said needle, whereby a stitch is formed first on one'side andtheii the other of said finger and zig-zag stitches produced, means for suspend ng thevibratioiis of said needle \vhereby theneedle fOl'lTlSSUlGllCs ,on one side of said finger and straightaway stitching produced, a tension dev1ce,"and means operating in connection" with'said tensiondevice for decreasing the tension on the needle thread when formingtlie stitches on fir'st' one side andthen the. other of said finger.

3. In a sewing machine, the combination of a Woi'ksupport, a presser'foot, a slack thread forming finger,- stitch forniing mech anism, including a needle, means for vibrating said needle whereby zigzag stitches areformed ac'ro-sssaid tliread finger, means for suspending the vibrations of said needle,

formed at one side of said stitch finger, a constant tensiondevi'ce and an auxiliary tension device, means operated by the means for causing the vibration of the needle for.

whereby a straight line of stitching is releasing theauxiliarytension when 'producing'zigzagstitching i 4. In a. sewing machine, I v of stitcliforming mechanism including a needle, means -for vibrating the same later- .the combination ally, devices for controlling the late'ral'iiiove,

.ment'of the needle, a tension device comprising tension disks, meansfor decreasing the tension includ ng 'an arm, a fork adgustahly carried thereby and adapted to enter between the disks of the tension, substantially as described.- H I Intestimony whereofi I ailix my signature, in presence of two witnesses.

DANIEL COREY.

L. V. RoAci-i, Einviss'r A. MUELLER.

I ll itnesses; 

